/***
 * vue-router 的 hash模式
 * ***/

let installed = false
let _Vue = null

class hashVueRouter {
    //这个是当运行Vue.use的时候调用的函数，作用是把vueRouter相关信息配置到全局
    static install(Vue) {
        //使用标志位进行判断：是否已经运行过Vue.use函数
        if (installed) return
        installed = true
        _Vue = Vue
        _Vue.mixin({
            //将相关信息在beforeCreate阶段进行混入
            beforeCreate() {
                //这句话是用来判断是否在vue实例上的
                if (this.$options.router) {
                    _Vue.prototype.$router = this.$options.router
                }
            }
        })
    }

    constructor(options) {
        //如果没有hash的话自动加上hash
        if (window.location.hash === "") window.location.hash = "/"
        this.options = options
        this.routerMap = {}
        this.data = _Vue.observable({
            current: window.location.hash.substr(1)
        })
        console.log(this.data.current)
        // this.data = {current:"/"}
        this.init()
    }

    init() {
        //向url中加入#
        // if(window.location.hash === '')window.location.hash="/#/"
        //初始化routerMap的映射
        this.createRouteMap()
        //初始化组件
        this.initComponent(_Vue)
        //初始化监听事件
        this.initOnHashChange()
    }

    createRouteMap() {
        this.options.routes.forEach(route => {
            this.routerMap[route.path] = route.component
        })
    }

    initComponent(Vue) {
        Vue.component("router-link", {
            props: {
                to: String
            },
            render(h) {
                return h("a", {
                    attrs: {
                        href: this.to
                    },
                    on: {
                        click: this.clickhander
                    }
                }, [this.$slots.default])
            },
            methods: {
                clickhander(e) {
                    window.location.hash = this.to
                    e.preventDefault()
                }
            }
        })
        const self = this
        console.log("self", self)
        Vue.component("router-view", {
            render(h) {
                //在这用的响应式数据
                const cm = self.routerMap[self.data.current]
                return h(cm)
            }
        })
    }

    initOnHashChange() {
        window.addEventListener("hashchange", () => {
            this.data.current = window.location.hash.substr(1)
            console.log(this.data.current)
        })
    }
}

export default hashVueRouter
